<!DOCTYPE html>    
    <html xmlns="http://www.w3.org/1999/xhtml">    
    <head>    
    <meta http-equiv="Content-Type" content="text/html; charset=gb2312" />    
    <title>无标题文档</title>    
    </head>    
  
    <body>    
    <p>    
    <video src="578df5e1e6953.mp4" controls preload="auto" id="player"></video>  
    </p>    
    <input name="submit" type="submit" onclick="getInfo()">    
    <p>    
  
    <script language="javascript">    
     var time;    
      function getInfo(){    
      var pl=document.getElementById("player");    
      time = pl.duration;  
       alert(time);  
     }    
    </script>    
    </p>    
    </body>    
    </html>
